Donepezil, a drug used to slow the onset of Alzheimer's disease, may help reverse dementia in patients who also have Down syndrome, according to researchers at the University of California at Irvine.

Many people with Down syndrome, a genetic disorder that causes mental retardation, also develop Alzheimer's symptoms.

In a pilot study, the California researchers gave donepezil for an average of 4 months to six patients with Down syndrome and compared them to nine Downs syndrome patients who did not get the drug.

Reporting in the Archives of Nehrology, the researchers said they observed "significant improvement in dementia scores for the treated group during a 3- to 5-month period."

Donepezil "may be helpful in reversing the symptoms of dementia during early and middle stages of cognitive decline," the researchers concluded.

They said the results of their small study suggested the need for a more extensive trial of donepezil as a treatment for patients with Down syndrome dementia.

Other sources: Archives of Neurology